curcumin and Submandibular-Gland-Neoplasms

Curcumin [1] is well known to possess apoptosis-inducing activity in some cancer cells, but little is known about its activity in normal cells of oral origin, such as HGF. The aim of the present study was to clarify the relationship between early apoptosis in HGF and the induction of reactive oxygen species (ROS) generation by curcumin.. We treated HGF and HSG cells with curcumin [1] and the related compounds biseugenol [2], eugenol [3], alpha-diisoeugenol [4], and isoeugenol [5] and measured cell survival (MTT method), ROS generation (DCFH-DA staining), and induction of early apoptosis. Early apoptosis was detected by monitoring loss of mitochondrial membrane potential (DeltaPsi(m)) by JC-1 staining and externalization of phosphatidylserine (PS) on the cell surface by annexin V-FITC/PI staining combined with flow cytometry.. The cytotoxic activities of curcumin [1] and [4] were similar and were nearly 10- to 100-fold stronger than those of the other compounds. Only curcumin was able to induce ROS generation and early apoptosis. Loss of DeltaPsi(m), PS externalization and ROS generation were significantly more pronounced in HGF cells than in HSG cells at curcumin concentrations lower than about 15microM, and were inhibited by the addition of the antioxidants N-acetyl-l-cysteine and glutathione.. The potent PS externalization and loss of DeltaPsi(m) in curcumin-treated HGF cells appears to be mediated by ROS generation.

Topics: Antineoplastic Agents; Apoptosis; Cell Survival; Cells, Cultured; Child; Curcumin; Dose-Response Relationship, Drug; Female; Fibroblasts; Gingiva; Humans; Membrane Potential, Mitochondrial; Phosphatidylserines; Reactive Oxygen Species; Submandibular Gland Neoplasms; Tumor Cells, Cultured

Curcumin is a well-known chemopreventive agent of oral cancers as well as stomach and intestinal cancers. The relationship between reactive oxygen species (ROS) production and cell membrane mobility was investigated to clarify the pro-oxidant mechanism of curcumin and tetrahydrocurcumin (TH-curcumin).. The intracellular ROS production and membrane mobility by curcumin or TH-curcumin were measured in human submandibular adenocarcinoma cells (HSGs) and human primary gingival fibroblasts (HGFs). ROS and mobility were measured by 5-(and -6)-carboxy-2',7'-dichlorofluorescein diacetate staining and fluorescence recovery after photo bleaching, respectively.. Curcumin produced ROS dose-dependently. ROS appeared in the region surrounding the cell membrane. The membrane mobility coefficient of the curcumin-treated cells was significantly lower than that of control cells. The lowered membrane mobility induced by curcumin was reversed by the addition of glutathione, an antioxidant. In contrast, TH-curcumin did not affect the ROS production or the membrane mobility coefficient. The alternations induced by curcumin treated HSG cells were greater than those by HGF cells.. The reduction in membrane mobility induced by curcumin was attributed to ROS production. The oxidative effects of curcumin may be related to the structure of the alpha, beta-unsaturated carbonyl moiety as well as the phenolic OH group of this compound.

Topics: Adenocarcinoma; Anticarcinogenic Agents; Antioxidants; Cell Line, Tumor; Cells, Cultured; Curcumin; Dose-Response Relationship, Drug; Fibroblasts; Fluorescence Recovery After Photobleaching; Gingiva; Humans; Membrane Fluidity; Molecular Structure; Oxidants; Reactive Oxygen Species; Submandibular Gland Neoplasms